A verification service can tell us that an address accepts mail, but it can't tell us that the person behind it still works there. We run two separate checks on every contact list before a single email goes out, and the first one is about the person, not the address. Our contact data accuracy page shows why we bother.
Why is a valid email not enough?
An address can pass every technical test and still be useless. The mailbox exists, the server answers, and the message lands in the inbox of a company the person left last spring. Either it goes to a colleague who never asked for it, or it sits unread.
The numbers on that page explain how common this is. We re-checked 123,241 contacts, and 34% came back with a different work email than the one we had on file. For 21% of them, the new address sat on a different company's domain. A list can look clean on paper while a fifth of it points at the wrong employer.
We hold a simple rule about this. If a person left the company, their work email is dead with them, even if the mailbox still answers today.
What are the two checks?
The first check asks whether the person still works at the company on the list. We look at their current LinkedIn profile and compare the employer with the account we're targeting. A database pass settles profiles seen on LinkedIn within the last 90 days, and a live look at the profile covers the rest.
The second check asks whether the address can receive mail. We confirm each address with a verification service before it goes anywhere near a sending tool. Our accuracy data covers 606,075 addresses checked this way, and about a third came back valid, a third unconfirmed, and a third undeliverable.
What order do we run the checks in?
We check employment first because a person who left makes the address question pointless. There's no reason to verify or hunt for the email of someone who won't read it. The employment result also decides how much email work is left to do.
We drop two verdicts only. Someone whose profile shows another employer is removed, and so is someone whose profile turns out to belong to a different person. A profile that won't load isn't evidence of anything, so that person stays in when the email verifies.
When can we reuse an address we already verified?
We don't re-verify everything every time. If an address got a send verdict within the last six months, we accept it as it stands. If the verdict is older, we accept it only when the person passed the live employment check that same day.
The logic is that someone who still works at the same place likely has the same address. The employment check does the work that a second email check would otherwise do.
Why do we compare the email domain to the company?
Tools that find emails look for the person, not for the company row we gave them. So a returned address can belong to a side job or an old employer and still verify as deliverable. In one run of 965 emails that looked ready to send, 128 of them, or 13%, sat on the wrong company domain.
We compare the domain on each address with the account domain and keep only the ones that match. We demote the rest to LinkedIn only. This costs us a few legitimate parent-company addresses, and we accept that trade over mailing the wrong company.
What do we do with catch-all addresses?
A catch-all server says yes to every address, so a verifier can't tell a real mailbox from a made-up one. These are the addresses where verification alone isn't enough. Our own bounce review found that a good verifier rarely fails us except on these domains, because nothing can succeed there.
We send every uncertain address through a second check built for catch-all servers. The ones that come back deliverable go out. The ones that stay unresolved go into a separate monitored group, and we watch that first batch before sending more. An address the second check calls undeliverable is dropped.
This also shows why we don't trust one verifier. In one calibration the first tool wrongly marked about four in ten good addresses as invalid, so blindly dropping its rejects would have thrown away good leads. When two tools disagree, the address goes to the cautious group and not the trash. Actual bounces from the sending tool remain the only real proof.
What does a LinkedIn list need on top of this?
Lists that go into LinkedIn outreach get the live profile check only, never the database shortcut. In one program, 212 pending leads had passed the database check, and a live re-check found 33 of them, or 16%, that should never have been queued. Some had left the company, some profiles belonged to the wrong person, and some links were dead.
Common questions
Is email verification enough before sending cold email?
Verification tells us an address accepts mail, but it can't tell us the person still works there. We check employment first and verify the address second.
How often does B2B contact data go out of date?
We re-checked 123,241 contacts, and 34% came back with a different work email than the one on file. For 21% of them, the new address sat on a different company's domain.
How do we handle catch-all email addresses?
We send them through a second check built for catch-all servers. The deliverable ones go out, the undeliverable ones are dropped, and the unresolved ones go into a separate group that we watch.
How long does a verified email address stay good?
We accept a send verdict for six months. An older verdict only counts when the person passed a live employment check that same day.